"Little sisters, sweethearts," members of a sub organization on campuses designed to assist the members of Alpha Phi Omega.  Phyettes are not the sisters of Alpha Phi Omega, but they are a female organization that usually chosen by the pledges of Alpha Phi Omega to assist them while pledging.  Other Phyettes, and sweets have became an official campus organization and pledge individuals into their membership.  Because of being "of" Alpha Phi Omega and because they are in a separate organization, they would be more of "little sisters" than they would be a sister to Alpha Phi Omega.

So what do you call a Jewel?

This depends on what the girls call themselves.  If they are a sweetheart organization like they are at Florida A&M University, then they would be little sisters or sweethearts.   However, the other entities of the national Jewel Organization with different "chapters" are sisters.  They are second sisters, but sisters none the less. 
 

So what do you call an APO female?

Brothers, Frats, or APOfemales.  There are some tendencies to call APO females sorors.  But that can't be.  It is only a attempt at correcting what just doesn't seem right in the first place. That is calling APO females, brothers.  But you have to be in a sorority to be a soror.  And the National and official title of an female that is in Alpha Phi Omega is "brother".  The reason that they are not apart of the 25/52 family is that they are not a product of all male chapters which didn't vote for their membership.  Ever since their introduction into Alpha Phi Omega their has been a decline in the membership of Gamma Sigma Sigma.  Where there is an Coed chapter of Alpha Phi Omega there is usually more so competition for membership and service than their is support for each service entity. Coed chapters are usually to themselves and consider themselves a separated entity.  This is a fact of Alpha Phi Omega.  Alpha Phi Omega "is" a separate entity.  However, the 25/52 family is a joint support effort.  You will never see a coed chapter unanimously decide to establish our sisters of Gamma Sigma Sigma on their campus.  In result, this is the death of the growth of the 25/52 family.
 

So what do you call an Omega Phi Alpha?

They were sisters to a few chapters of Alpha Phi Omega. They exist on about 15 or so campuses. The only campus that I am aware might still have a brother sister relationship is Aurburn. They never became a nationally recongnized sister sorority of Alpha Phi Omega. However, because they have an historical association with Alpha Phi Omega, I think they should be considered as sisters or sorors as well, even though they only became a national entity in 1967.  
 

So what do you call a Gamma Sig?

Sorors, sisters.  Gamma Sigma Sigma's founder Marvyn Glover, told me that It was always the intentions of Gamma Sigma Sigma to be sisters of Alpha Phi Omega

I would call them sisters
 

How bout a APO Female or Phyette that has become a Gamma Sigma Sigma sister.

I would call her my sister or a soror.  It would be my suggestion that if you are a Phyette that while it is okay to remain a Phyette, that you you give yourself the opportunity to be apart of a national sorority, be it Gamma Sigma Sigma, Omega Phi Alpha, The Jewels Organization or any Counciled Greek-lettered organization.  And if you are a female in Alpha Phi Omega, you too should give yourself the opportunity to be apart of a national sorority, be it Gamma Sigma Sigma, Omega Phi Alpha, The Jewels Organization or any Counciled Greek-lettered organization.  At the point of becoming both you can decide what you want to be called.  But at least you gave yourself that opportunity.  No matter how much you sororitize a non-sorority, you always will be missing something special.